Device for maintaining the working surface of the grinding disk in grinding machines



Nov. 15, 1927. u 1,649,713

A F. 'r. LOFQUIST DEVICE FOR MAINTAINING THE WORKING SURFACE'OF was GRINDING DISK IN GRINDING MACHINES Filed Jul 29. 1921 2 Sheets-Sheet 1 FQ LZ. 2

INVENTOR 24, ffi Mr ATTORNEY5 Nov. 15, 1927.

A. F. T. LbFQUIST DEVICE FOR MAINTAINING THE WORKING SURFACE OF THE GRINDING DISK IN GRINDING MACHINES Filed July 29. 1921 2 Sheets-Sheet 2 INVENTOR Q 2 jmlac 7 a 2110/? 5Y5,

Patented Nov. 15, 1927..

UNITED STATES PATENT OFFICE.

AXEL FREDRIK THURE L6FQIIIST, OF U'IIBYNAS VILLASTAD; NEAR GdTTENBORG,

SWEDEN, ASSIGNOR TO AKTIEBOLAGET SVEN-SKA KULLAGERFABBIKEN, OF GOT- TENBORG, SWEDEN, A CORPORATION OF swnnnn.

DEVICE FOR MAINTAINING THE WORKING SURFACE OF THE GRINDING DISK IN GRINDING MACHINES. v

Application filed July 29, 1921, Serial No.

The present invention relates to av device for maintaining the form and position of i the working surface of the grinding disk in grinding machines. The object of the inven t1 tion is to enable the operator to determine the momentwhen the working surface of the grinding disk takes up a predetermined position, to maintain it in such position and to maintain the form of the'working surface w of the grindingdisk. The invention consists, essentially, in the grinding machine being provided with a. feed device for the grinding disk, said feed device working continuouslyor at definite intervals, and also 145 with a rotary dressing or abrading member for the working surface of the grinding disk. The working surface of the dressing member, or the part thereof engaging the working surface of the grinding disk, is suitably maintained in a predetermined position dependent on the final form. or dimensions. of the work piece to beground, so that it will be possible to decide, bythe formation of sparks between the working surfaces of the dressing member and the grinding disk, when the said surfaces enter into engagement, i. e. the moment when the working surface of the grinding disk takes up the desired position. The continuous or intermittent feed ing of the grinding disk. which shall be regulable in amount, should be chosenso as to be greater than the wear of the grinding disk caused by the workpiece alone but equal or substantially equal to the wear caused by the "dressing member and the work piece jointly, so that an effectivegrinding is obtained and the pressure between the grinding disk and the dressing member will not be too great. The shape of the working surface of the dressing member is dependent on. of the working surface of the grinding The invention is illustrated schematically in the annexed drawing. Fig. 1 is a longitudinal section of a device according to this invention. Fig. 2 is a cross-section on line AB of Fig. 1. Figs. 3 and 4 show an application of the device in grinding gear wheels.

Referring to Figs. 1 and 2, 1 designates a frame on which a slide 2 is movable, said. slide forming a bearing for the grinding disk.

tion disk 11.

488,273, and in Sweden August 21, 1920.

5 is effected by a screw 6 journaled in the frame 1, said screw being driven by a worm wheel-7 engaged by a worm 8. Attached to the worm 8, which is journaled in the frame in suitable manner, is a second worm wheel 9 engaged by a worm 10 likewise journaled in the frame 1 and firmly connected to a fric- .Tournaled in the upper part of the frame 1 is, further, a second friction disk 12 carrying a belt pulley; and mounted between the friction disks 11 and 12.is a

radially adjustable friction roller 13 by which the ratio of gearing between the disks 11 and 12 can be varied. If the friction disk 12 is rotated. the friction disk 11 will, obviously, also rotate, through the medium of the roller 13. and so will also the screw 6,

through the medium of the worm gears 7,

moved towards the work piecefi with a speedwhich', on account of the chosen elements of translation (worm gears), will be very. small and, by suitably adjusting the friction roller 13, can be made slightly greater than the wear of the grinding disk caused by the Work piece 5, the pressure between the grinding disk and the work piece being easily determined with regard to the formation of sparks. Longitudinally movably but nonrotatably mounted on the shaft 14 is. further, a dressing or abrading member 15 the working surface 16 of which, in the form of embodiment shown, is annular in shape, and plane. The dressing member 15 is kept pressed, by a spring 17 placed around the shaft 14, against contact devices illustrated in the formof rollers 18 rotatably journaled in'a slide 19 adjustably mounted in the frame 1 and secured in place by some suitable means, as a screw 19 as shown. Said slide serves at the.same time as a bearing for'the shaft 14, throughthe medium of'a sleevelike prolongation 20 of the member 15. The position of the working surface 16 of the 'member 15 is this fully determined by the rollers 18, and by adjusting the slide 19 with the rollers 18 in such manner that the tangent plane of the rollers (corresponding to line A--B of Fig. 1) is at a distance from the axial line 21 of the work piece 5, which is equal to the final desired radius of the work piece 5 or, generally, corresponds-to a desired dimension, it is, thus, possible to 'decide when this dimension has been attained, inasmuch as parts 3 and 15 will then so come in contact as to form sparks between them. The fact that the member 15 can also be worn is, obviously, insignificant, since, through the action of the spring 17 the position of its working surface 16 is fully determined b the rollers 18. By so choosing the feed 0 the grinding disk that, as hereinbefore mentioned. it will be equal or substantially equal to thewear ofthe grinding disk caused by the work piece and the dressing member jointly, the working surface of the grinding disk will, obviously. always take up the position determined by the dressing member, orthe rollers 18, and, through the action of the rotary dressing member, maintain its plane form. These circumstances, viz the maintaining of the working surface of the grinding disk in a fixed position and the maintaining of the plane form of its working surface, are known to be of considerable importance. especially in grinding tooth profiles according to the rolling principle, the working surface then representing a tooth side or part thereof in a theoretical or imagined generating rack. or an imagined generating wheel, the position and form of which are not allowed to be changed.

In Figs. 3 and 4, an application of the arrangement .for grinding gear wheels according to the rolling principle is schematically illustrated. 3 designating. as in Figs. 1 and 2..the grinding disk fed with the speed hereinbefore mentioned. said disk having here the shape of a plate, and 15 designating the rotary dressing or abrading member fixed in position. The working surface 22 of the grinding disk. the position of which is fully determined. as hereinbefore' mentioned. by the working surface 16 of the dressing member. represents a tooth side in an imagined generating rack 23. It is essential to maintain the form of the working surface of the grinding disk, which, in the illustrated form, is plane.

In both forms shown in the drawings the peripheral speed is greater at the outer circumference of the annular working surface 22 than at the inner circumference, the wear of the. grinding disk, in grinding certain forms as for instance a tooth profile. would, if no measures to the contrary were taken, be greater at the outer circumference than at the inner circumference. i. e. the working surface of the grinding disk would not maintain its plane form but would obtain a curved profile. -The dressing or abrarding member 15 is, therefore, to be arranged in such manner as to exert a greater abrading action at the inner circumference of the surface 22 of the grinding disk than at the outer circumference. This can be attained by the working surface 16 of the dressing member being annular in shape, as shown, and by the same being placed in such manner relatively to the workin surface 22 of the grinding disk that, as c early shown in Fig. 4, the engagement of each element of said surfaces 16 and 22 takes place during a longer time at and near the inner circumference of the surface 22 of the grinding disk than at the outer circumference.

While the working surface of the grinding disk in relation to that of the dressing member is such as shown in Figs. 3 and 4 as to exert a greater abrading action at the inner circumference of the surface of the grinding disk than at the outer circumference as above explained, it is obvious that the corresponding parts shown in Figs. 1 and 2 may be similarly disposed to bring aboutthis action, no change in the construction of the parts being necessary other than an increase of the inner diameter of the grinding surface 22 to cause said surface to occupy the same relation to the surface 16 as is shown in Fig. 3.

The working surface of the dressing memher need not be plane since it is. obviously, dependent on the form to be given to the working surfaces of the grinding disk. It is also obvious that if desired,-the feed of the grinding disk need not be continuous.

I claim:

1. An arrangement for maintaining the form and position of the working surface of the grinding disk in grinding machines, characterized by an annular grinding disk, a feed device for the grinding disk and by a rotary annular dressing or abrading member with which the annular working surface of i the grinding disk is maintained in engagement.

2. An arrangement according to claim 1, characterized by the grinding disk being automatically feed forward more than the wear of the grinding disk caused by the work piece alone but equal or substantially equal grinding disk as to exert a less abrading action at and near the outer circumference of the grinding disk than at places located gea'er to the axis of rotation of the grinding 6. An arrangement according to claim 1, characterized by the workin surface of the dressing or abrading member being kept pressed, through the action of a spring or the like, againstan adjustable device consisting, suitably, of rollers rotatably journaled in an adjustable slide or the like, whereby the working surface of the dressing members is held in a fixed predetermined position so far as inward movement is concerned.

7. In a mechanism of the type described, I

the combination of a rotary grinding member, a rotary dressing member adapted to act on the working surface of the grinding member, a contact device normally in engagement with the working surface of the dressing member and adjustable to position said surface at a predetermined relation to the final surface of the work to be ground, means for maintaining the engagement of the working surface of the dressing member with said contact device, and means for feeding the grinding member to engage the Working surface of the dressing member and to act on the work.

8. In a mechanism of the type described, the combination of a rotary grinding member, .a rotary dressing member adapted to act on the working surface of the grinding member, a series of contact rollers normally in engagement with the working surface of the dressing member and adjustable to position said surface at a predetermined relation to the final surface of the work to be ground, means for maintaining the engagement of the working surface of the dressing member with said contact rollers, and means for feeding the grinding member to engage the working surface of the dressing member and to act on the work.

9. In a mechanism of the type described, the combination of a rotary grinding member, a rotary dressing member adapted to act on the working surface of the grinding member, a contact device engaged by the working surface of the dressing member and adjustable to osition said surface at a predetermined re ation to the final surface of the work to be ground, means for yieldingly maintaining the engagement of the working surface of the dressing member with said contact device, and means for feeding the grinding member to enga e the working I surface of the dressing mem on the work.

10. In a mechanism of the type described, the combination of a rotary grinding memher, a rotary dressing member adapted to act on the working surface of the grinding member, a series of contact rollers engaged by the working surface of the dressing member and'adjustable to position said surface at a predetermined relation to the final surface of the work to be round, means for yieldingly maintaining the engagement of the dressing member With said contact rollers, and means for feeding the grinding member to engage the working surface of the dressing member and to act on the work.

11. The combination of a rotary grinder er and to act of annular form, a rotary dressing member of annular form adapted to engage the working surface of the grinder, and a series of rollers engaging the working surface of the dressing member for determining the position of the working surface of the grinder, the organization of the parts being such that the working surfaces of the grinder and of the dressing member are disposed in the same plane when in working relation.

12. The combination of a rotary grinder of annular form, a rotary dressing member of annular form adapted to engage the working surface of the grinder, a series of rollers engaging the working surface of the dressing member for determining the position of the working surface of the grinder, the organization of the parts being such that the working surfaces of the grinder and of the dressing member are disposed in the same plane when in working relation, and

means for shifting said rollers for adjust-' ing the position of the said plane.

In testimony whereof I have signed my name.

AXEL FREDRIK THURE LOFQUIST. 

